Dipolar NMR relaxation of nonprotonated aromatic carbons in proteins. Structural and dynamical effects.

abstract：:Closing linear poly(ethylene glycol) (PEG) into a circular "crown" dramatically changes its dynamics in the alpha-hemolysin channel. In the electrically neutral crown ether (C2H4O)6, six ethylene oxide monomers are linked into a circle that gives the molecule ion-complexing capacity and increases its rigidity. As with...

journal_title：Biophysical journal

authors： Bezrukov SM,Krasilnikov OV,Yuldasheva LN,Berezhkovskii AM,Rodrigues CG

更新日期：2004-11-01 00:00:00

abstract：:Five molecular dynamics computer simulations were performed on different phospholipid:sterol membrane systems in order to study the influence of sterol structure on membrane properties. Three of these simulated bilayer systems were composed of a 1:8 sterol:phospholipid ratio, each of which employed one of the sterol m...

journal_title：Biophysical journal

authors： Smondyrev AM,Berkowitz ML

更新日期：2001-04-01 00:00:00

abstract：:Spatial patterning of biochemical cues on the micro- and nanometer scale controls numerous cellular processes such as spreading, adhesion, migration, and proliferation. Using force microscopy we show that the lateral spacing of individual integrin receptor-ligand bonds determines the strength of cell adhesion. For spa...

journal_title：Biophysical journal

authors： Selhuber-Unkel C,Erdmann T,López-García M,Kessler H,Schwarz US,Spatz JP

更新日期：2010-02-17 00:00:00

abstract：:We report on the application of two photon molecular excitation to fluorescence correlation spectroscopy. We demonstrate the first fluorescence correlation spectroscopy measurements of translational mobility in the cytoplasm of living cells. Two-photon excitation inherently excites small sample volumes in three dimens...

journal_title：Biophysical journal

authors： Berland KM,So PT,Gratton E

更新日期：1995-02-01 00:00:00

abstract：:The electric quadrupole moment of the deuterium nucleus provides a nuclear magnetic resonance (NMR) probe of electric field gradients, and thereby of organization of tissue water. 8-17% of H(2)O in rat muscle and brain was replaced by D(2)O from 50% deuterated drinking water. The peak height of the steady-state NMR sp...

journal_title：Biophysical journal

authors： Cope FW

更新日期：1969-03-01 00:00:00

abstract：:Single-molecule methods provide direct measurements of macromolecular dynamics, but are limited by the number of degrees of freedom that can be followed at one time. High-resolution rotor bead tracking (RBT) measures DNA torque, twist, and extension, and can be used to characterize the structural dynamics of DNA and d...

journal_title：Biophysical journal

authors： Ivanov IE,Lebel P,Oberstrass FC,Starr CH,Parente AC,Ierokomos A,Bryant Z

更新日期：2018-01-23 00:00:00

abstract：:Alterations in bone tissue composition during osteoporosis likely disrupt the mechanical environment of bone cells and may thereby initiate a mechanobiological response. It has proved challenging to characterize the mechanical environment of bone cells in vivo, and the mechanical environment of osteoporotic bone cells...

journal_title：Biophysical journal

authors： Verbruggen SW,Mc Garrigle MJ,Haugh MG,Voisin MC,McNamara LM

更新日期：2015-04-07 00:00:00

abstract：:Giant vesicles formed of 1,2-dipalmitoylphosphatidylcholine (DPPC) and sterols (cholesterol or ergosterol) in water and water/ethanol solutions have been used to examine the effect of sterol composition and ethanol concentration on the area compressibility modulus (K(a)), overall mechanical behavior, vesicle morpholog...

journal_title：Biophysical journal

authors： Tierney KJ,Block DE,Longo ML

更新日期：2005-10-01 00:00:00

abstract：:Many aspects of chromatin biology are influenced by the nuclear compartment in which a locus resides, from transcriptional regulation to DNA repair. Further, the dynamic and variable localization of a particular locus across cell populations and over time makes analysis of a large number of cells critical. As a conseq...

journal_title：Biophysical journal

authors： Zhao Y,Schreiner SM,Koo PK,Colombi P,King MC,Mochrie SG

更新日期：2016-07-12 00:00:00

abstract：:We have used optical tweezers to study the elasticity of red cell membranes; force was applied to a bead attached to a permeabilized spherical ghost and the force-extension relation was obtained from the response of a second bead bound at a diametrically opposite position. Interruption of the skeletal network by disso...

journal_title：Biophysical journal

authors： Sleep J,Wilson D,Simmons R,Gratzer W

更新日期：1999-12-01 00:00:00

abstract：:The glycocalyx is a thick coat of proteins and carbohydrates on the outer surface of all eukaryotic cells. Overproduction of large, flexible or rod-like biopolymers, including hyaluronic acid and mucins, in the glycocalyx strongly correlates with the aggression of many cancer types. However, theoretical frameworks to ...

journal_title：Biophysical journal

authors： Gandhi JG,Koch DL,Paszek MJ

更新日期：2019-02-19 00:00:00

abstract：:Changes in free energy are normally used to track the effect of temperature on the stability of proteins and hydrophobic interactions. Use of this procedure on the aqueous solubility of hydrocarbons, a standard representation of the hydrophobic effect, leads to the conclusion that the hydrophobic effect increases in s...

journal_title：Biophysical journal

authors： Schellman JA

更新日期：1997-12-01 00:00:00

abstract：:Calculations are reported of the time-dependent Nernst-Planck equations for a thin permeable membrane between electrolytic solutions. Charge neutrality is assumed for the time-dependent case. The response of such a membrane system to step current input is measured in terms of the time and space changes in concentratio...

journal_title：Biophysical journal

authors： COHEN H,COOLEY JW

更新日期：1965-03-01 00:00:00

abstract：:Recent advances in imaging technology have revealed oscillations of cyclic adenosine monophosphate (cAMP) in insulin-secreting cells. These oscillations may be in phase with cytosolic calcium oscillations or out of phase. cAMP oscillations have previously been modeled as driven by oscillations in calcium, based on the...

journal_title：Biophysical journal

authors： Peercy BE,Sherman AS,Bertram R

更新日期：2015-07-21 00:00:00

abstract：:The effect of a transmembrane peptide on the domain structure of a two-component, two-phase lipid bilayer composed of dimyristoyl phosphatidylcholine (DMPC) and distearoyl phosphatidylcholine (DSPC) was examined by spin label electron spin resonance (ESR) spectroscopy. The peptide, pOmpA, is the hydrophobic, 25-residu...

journal_title：Biophysical journal

authors： Sankaram MB,Marsh D,Gierasch LM,Thompson TE

更新日期：1994-06-01 00:00:00

abstract：:The interactions of the hydrophobic pulmonary surfactant proteins SP-B and SP-C with 1,2-dipalmitoylphosphatidylcholine in mixed, spread monolayer films have been studied in situ at the air/water interface with the technique of external reflection absorption infrared spectroscopy (IRRAS). SP-C has a mostly alpha-helic...

journal_title：Biophysical journal

authors： Pastrana-Rios B,Taneva S,Keough KM,Mautone AJ,Mendelsohn R

更新日期：1995-12-01 00:00:00

abstract：:Multiple data are available on the self-assembly of mixtures of bilayer-forming amphiphiles, particularly phospholipids and micelle-forming amphiphiles, commonly denoted detergents. The structure of such mixed assemblies has been thoroughly investigated, described in phase diagrams, and theoretically rationalized in t...

journal_title：Biophysical journal

authors： Lichtenberg D,Ahyayauch H,Goñi FM

更新日期：2013-07-16 00:00:00

abstract：:Proteins are denatured in aqueous urea solution. The nature of the molecular driving forces has received substantial attention in the past, whereas the question how urea acts at different phases of unfolding is not yet well understood at the atomic level. In particular, it is unclear whether urea actively attacks fold...

journal_title：Biophysical journal

authors： Stumpe MC,Grubmüller H

更新日期：2009-05-06 00:00:00

abstract：:Perfusion is one of the most important processes maintaining organ health. From a computational perspective, however, perfusion is among the least-studied physiological processes of the heart. The recent development of novel nanoparticle-based targeted cardiac therapy calls for novel simulation methods that can provid...

journal_title：Biophysical journal

authors： Diem AK,Valen-Sendstad K

更新日期：2019-12-17 00:00:00

abstract：:An approach is described using fluorescence resonance energy transfer (FRET) to detect inhomogeneity in lipid organization, on distance scales of the order of tens of nanometers or greater, in lipid bilayers. This approach compares the efficiency of energy transfer between two matched fluorescent lipid donors, differi...

journal_title：Biophysical journal

authors： Silvius JR

更新日期：2003-08-01 00:00:00

abstract：:A filopodium is a cytoplasmic projection, exquisitely built and regulated, which extends from the leading edge of the migrating cell, exploring the cell's neighborhood. Commonly, filopodia grow and retract after their initiation, exhibiting rich dynamical behaviors. We model the growth of a filopodium based on a stoch...

journal_title：Biophysical journal

authors： Lan Y,Papoian GA

更新日期：2008-05-15 00:00:00

abstract：:The redox-driven proton pump cytochrome c oxidase is that enzymatic machinery of the respiratory chain that transfers electrons from cytochrome c to molecular oxygen and thereby splits molecular oxygen to form water. To investigate the reaction mechanism of cytochrome c oxidase on the single vibrational level, we used...

journal_title：Biophysical journal

authors： Heitbrink D,Sigurdson H,Bolwien C,Brzezinski P,Heberle J

更新日期：2002-01-01 00:00:00

abstract：:The polar interface of membranes containing phosphatidylglycerol or cholesterol was studied by (2)H nuclear magnetic resonance (NMR) as a function of membrane hydration. The membranes were macroscopically aligned and hydrated with deuterium oxide. Water uptake and membrane annealing was achieved under NMR control, usi...

journal_title：Biophysical journal

authors： Kurze V,Steinbauer B,Huber T,Beyer K

更新日期：2000-05-01 00:00:00

abstract：:Electron paramagnetic resonance spectroscopy was used to monitor the orientation of muscle cross-bridges attached to actin in a low force and high stiffness state that may occur before force generation in the actomyosin cycle of interactions. 2,3-butanedione monoxime (BDM) has been shown to act as an uncompetitive inh...

journal_title：Biophysical journal

authors： Zhao L,Naber N,Cooke R

更新日期：1995-05-01 00:00:00

abstract：:Many cell cytoskeletons include an aster of microtubules, with the centrosome serving as the focal point. The position of the centrosome within the cell is important in such directional activities as wound closure and interactions of immune cells. Here we analyzed the centrosome positioning as it is dictated by microt...

journal_title：Biophysical journal

authors： Maly VI,Maly IV

更新日期：2010-11-03 00:00:00

abstract：:Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) are the main lipid components of the inner bacterial membrane. A computer model for such a membrane was built of palmitoyloleoyl PE (POPE) and palmitoyloleoyl PG (POPG) in the proportion 3:1, and sodium ions (Na+) to neutralize the net negative charge on each...

journal_title：Biophysical journal

authors： Murzyn K,Róg T,Pasenkiewicz-Gierula M

更新日期：2005-02-01 00:00:00

abstract：:Diluted bull semen samples were bombarded with a 24 Mev proton beam. Dose response curves for the fraction of cells which survived the bombardment and for the average velocity of the surviving cells were measured. Target theory indicated a cross section of the sensitive volume of 2.1 x 10(-10) cm(2). Respiration measu...

journal_title：Biophysical journal

authors： Rikmenspoel R,van Herpen G

更新日期：1969-06-01 00:00:00

abstract：:The elastic theory of flexural waves in thin rods accurately predicts the velocity of flagellar bending waves over a wide range of viscosities. This shows that flagella behave as a purely mechanical system for the transmission of these waves. An evaluation of the total bending moment reveals that this moment occurs in...

journal_title：Biophysical journal

authors： Rikmenspoel R

更新日期：1971-05-01 00:00:00

abstract：:Mammalian sperm traverse several layers of egg vestments before fertilization can occur. The innermost vestment, the zona pellucida, is a glycoprotein shell, which captures and tethers the sperm before they penetrate it. We report here direct measurements of the force required to tether a motile human sperm as well as...

journal_title：Biophysical journal

authors： Baltz JM,Katz DF,Cone RA

更新日期：1988-10-01 00:00:00

abstract：:The solubility of aqueous solutions of lysozyme in the presence of polyethylene glycol and various alkaline salts was studied experimentally. The protein-electrolyte mixture was titrated with polyethylene glycol, and when precipitation of the protein occurred, a strong increase of the absorbance at 340 nm was observed...

journal_title：Biophysical journal

authors： Boncina M,Rescic J,Vlachy V

更新日期：2008-08-01 00:00:00